Island



' (No Model.)

0. E. GREENE.

RIFFLE PLATE.

No, 599,128. Patented Feb. 15, 1898.

UNITED STATES" PATENT OFFICE,

CHARLES E. GREENE, OF PROVIDENCE, RHODE ISLAND.

SPECIFICATION forming part of Letters Patent No. 5 99,128, datedFebruary 15, 1898. Application filed May 10, 1897. Serial No. 635,804.(No model.)

To aZZ whom it concern.-

Be it known that 1, CHARLES E. GREENE, a citizen of the United States,residing at Providence, in the county of Providence and State of RhodeIsland, have invented certain new and useful Improvements in Rifiie-Plates; and I do hereby declare the following to be a full, clear, andexact description of the invention, such as will enable others skilledin the art to which it appertains to make and use the same, referencebeing had to the accompanying drawings, and to letters of referencemarked thereon, which form a part of this specification.

My invention relates to improvements in riffle-plates, so called,employed in goldcollecting apparatus or amalgamators.

In the construction of riffle-plates as hitherto made it has been usual,so far as I am aware, to cast or form the riffles or ribs integral withthe plate or base, the entire surface of the plate, including the ribs,being covered with the quicksilver composition or amalgam, although insome cases riffle-plates have been devised in which mercury-holdingtroughs have been removably secured to one or both ends of the'plates.

' I am aware of the fact that it has been proposed to employ cast-ironsluice-boxes the the particles of fine gold mingled with the sand andflowing over the surface of the sluicebox.

' In such former construction the action of the sand and water flowingover the face of the plates operates to wear off the amalgam from thetops of the ribs or riflles, thereby impairing the efficiency anddurability of the plates, and in cases where the plates are composed,say, of comparatively soft metal, as copper or composite metal, theforce of the sand soon cuts through the ribs, thus necessitatingcorrespondingly frequent renewals of the plates and greatly increasingthe cost of maintenance.

The object I have in view is to produce a rifile-plate possessingsuperior advantages and one in which the disadvantages or objectionsinherent in former devices of this class are practically eliminated.

To that end my invention consists, essentially, of a plate member ofhard metal, as cast-iron, provided with a series of integrallyformedraised ribs or riflies and a corresponding series of suitably-shapedinsertible amalgam or gold collecting lining pieces or strips mounted inthe grooves or channels formed between the riftles, all as hereinafterset forth and claimed.-

In the accompanying sheet of drawings, Figure 1 is a perspective View ofa sluice or trough provided with my'improved riffleplates, a portion ofthe front side being broken away. Fig. 2. is a plan view, in enlargedscale, of one of the plates or sections. bottom view. Fig. 4 is atransverse section, enlarged, taken on line so :20 of Fig. 2. Fig. 5 isa perspective view of one of the gold-collecting lining pieces orstripsdetached from the plate and Fig. 6 is a sectional view similar to Fig.4, the lining-pieces being omitted.

In the drawings, A designates an amalgam or gold collecting plate orsection embodying my improvement, its size being, say, one foot square.I prefer to arrange and mount these plates end to end in the base of asuitable trough or sluice, substantially as shown in Fig. 1, thusforming a practically-continuous plate having any proper length. Theadja cent edges of the sections may be machined and having a packing pof rubber between them, if desired.

The base or holder member a of my improved plate A may be made of Icast-iron or other suitable material and provided on its upper or faceside with a series of transverselyarranged ribs or riffles c integraltherewith. The form and size of these ribs may be varied, according tothe class of gold-bearing material or finely-divided ore employed. At ornear the base of the ribs 0 the latter are provided with shoulders c,the intervening .part of the plate uniting each pair of ribs beingconcave and forming a seat or support (1 for the correspondingly shapedinsertible goldcollecting or amalgam lining member I) about to bedescribed.

Fig. 3is a The form of these concave ioo or grooved seats cl may bevaried at will, although. the shape represented in the drawings producesgood results.

In order to strengthen the base-casting a, it may be provided on itsunder side with thin stiffening-ribs 0, extending downwardly from andcoextensive with the riffies c. The plate is further strengthened by theaddition on its under side of other ribs e, formed at substantiallyright angles with and intersecting the ribs 6, substantially asrepresented in the drawings. The ribs 6 e render the plate strongerwithout materially increasing its weight and at the same time serve tokeep it from warping.

The amalgam or gold collectinglining members b may be made of anysuitable metal, as copper, of even a composition of metals susceptibleor retaining successive layers or applications of the quicksilversolution. These lining members I) may be cast or otherwise produced,their form cross-sectionally being substantially the counterpart of thesaid concave seats (I. The edges of the pieces 17 may be dressed off, ifdesired, so as to fit snugly into and completely cover the seat and abutagainst the shoulders c of the riffles c.

A series of my improved properly-prepared plates A may be arranged in aninclined trough B, substantially as shown in Fig. 1. I prefer to employthe wet process in separating or collecting the fine particles of goldfrom the sand or materialthat is, the goldbearing sand or quartz, in afinely-divided state, is shoveled or charged onto the upper part of thetrough, at the same time directing a stream of water onto the material,as usual. The thus-mingled sand and water flows downwardly over thesurface of the plates and passes off at the lower end as tailings. Theriffles operate, as is well known, to interrupt the passage of theflowing material, thereby insuring that all parts of the latter will bebrought into contact with the amalgam-covered or gold-collectingremovable strips b, and as these members I) have (through the propertiesof the mercury with which they are faced) an affinity for the gold thegreater portion of the atoms of the latter metal will be arrested andretained on the surface of the said members I), the sand and othermaterial or inferior metals at the same time flowing off to waste.

It will be apparent that the principal part of the wearing effect of thesand, &c., occurs at the top of the riffies or ribs 0. These are or maybe made integral with the base member a and formed of cast-iron or othersuitable resisting metal, thereby adapting them to wear a comparativelylong time. The goldcollecting or amalgam-covered members 5 are mountedin the transversely-arranged seats d, located at the base of the rifilesand secured in place by the sides of the trough. These pieces I) may bemade of copper and covered on their upper faces with mercury in anysesses considerable thickness, after which the sides of the trough maybe removed-and the several amalgam-covered members I) pushed endwisefrom the plates and then scraped or otherwise treated to remove theamalgam from them. Meanwhile, if desired, another set of prepared piecesI) may be inserted into the plates and the operation of sand-washingcontinued, as before described. The several pieces I) areinterchangeable, so that no difficulty is experienced in removing themfrom or inserting them into the base-plate a. As thus constructed, myimproved compound plates A are far superior and much more durable thansingle-member plates of this class as usually made, wherein the amalgamcovers practically the entire surface of the plate, including theriffles.

By reversing the arrangement of the plates A in the trough B, so thatthe flow of water, &c., is in the direction of the inclined side of theriffle, (see arrow m, Fig. 4B,) the space at the base of the rifflesmay, if desired, be used as a pocket for free mercury, since thearrangement is such that the force of the water would not then dislodgeit. If, however, the direction of the water be reversed, so as to passover the riffles in the opposite way, (see arrows 0, Figs. 1 and 4,) itsforce would quickly expel the free mercury, the latter then flowing oifat the end of the trough into the tailings and becoming lost.

In lieu of withdrawing the charged goldcollecting shells or liningmembers I) from the base-plate a,su bstantially as before described,

for the purpose of removing the gold or amalgam therefrom, the entireplate A may be detached from the trough B and another or uncharged platesubstituted for it. If desired, the dimensions or area of thegold-collecting or exposed surface may be increased by simplymultiplying the plates A sidewise.

I claim as my invention and desire to secure by United States LettersPatent- 1. As an improved article of manufacture, a gold-collectingriffie-plate for sluice-boxes, the same consisting of a cast or othersuitably-formed integral metallic base member provided with a series oftransversely-arranged raised parallel ribs or riffles separated fromeach other longitudinally of the said base plate or member and forminggrooves or channels between them, and a corresponding series ofgold-collecting or amalgam shells b of less hardness than said basemember removably secured to the base and located in the lower portion ofthe channels formed between the said ribs, the upper or crest portion ofthe latter being directly exposed to the action of the material or oreflowing over the plate, substantially as described.

2. In a gold-collecting riffle-plate, the combination with thehard-metal base member at having a series of suitably-shapedtransversely-arranged parallel raised ribs 0, and seats at in the lowerportion of the channels between the ribs and terminating in shoulders 0formed in the sides of the ribs, of the removable thin gold-collectingstrips or shells b mounted on said seats and in engagement with theshoulders thereof,' and having the outer surface of the ribs above saidshoulders substantially even or flush with the upper or working surfaceof the shells 12, substantially as hereinbefore described and for thepurpose set forth.

In testimony whereof I have affixed my signature in presence of twowitnesses.

CHARLES E. GREENE.

Witnesses GEO. H. REMINGTON, REMINGTON SHERMAN.

